1) TECHNICAL FIELD
The subject invention relates to a capless assembly for the refueling of automotive fuel tanks.
2) DESCRIPTION OF THE PRIOR ART
Most vehicle fuel tanks include a filler neck extending from the tank to allow a user to refill the tank with fuel. Some type of cap or cover is placed over the filler neck in order to seal the fuel tank from the atmosphere. The most common type of cover is a gas cap. Conventional gas cap assemblies are typically threaded onto the filler neck and include some type of locking handle. To fill the fuel tank a user must completely remove the gas cap from the filler neck.
The prior art has also contemplated the use of a pivotal cover moveable between open and closed positions to open and close the filler neck. These prior art designs have a pivotal cover mounted within a removable gas cap. An advantage of these designs is that the user does not have to remove the gas cap to fill the fuel tank. One such design also has the cover linked to a outer filler door such that when the filler door is opened the cover automatically opens. Examples of these prior art designs are disclosed in U.S. Pat. Nos. 5,720,328 to Ott and 5,735,424 to Diederiks, Jr. et al. These prior art gas cap assemblies have a number of deficiencies. One primary deficiency is that they do not provide an effective means for releasing pressurized fluid within the filler neck before the cover is opened. Over time, operating pressures and temperatures within the filler neck can approach dangerous levels, which may result in spraying fuel onto the user removing or opening the closure due to the quick pressure release when the cap, or closure, is removed. The dangers associated with opening a pressurized fuel tank can include affixation, burning, scorching, and various environmental hazards. Hence, it is desirable to ensure a gradual pressure decay within the fuel filler neck and fuel tank prior to removing the cap or opening the closure.